Changes in the Frequency of Extreme Warm Season Surface Dewpoints in the Midwestern U.S.: Implications for Weather-Related Hazards

Northern Illinois University, Dekalb IL

Investigators

Abstract

Land - atmosphere interactions in the Upper Midwest have been largely ignored even though it is a major agricultural region (i.e. corn and soybean) and is an area that experiences dangerous heat waves and frequent warm season thunderstorm development. Modeling studies suggest that land - atmosphere interactions in mid-continental locations are important for global induced climate changes and that even subtle land use changes may have important impacts on the occurrence of climate extremes. This study will develop a multi-decadal extreme dew point climatology, determine the temporal and spatial distribution of surface atmospheric moisture, and identify regions favorable to moisture pooling in the Upper Midwest. This will be achieved by integrating ground-based observations, high-resolution satellite data, and geographic information systems. These data and tools will allow the investigators to determine the role of land cover, vegetation (including agriculture), and topography in enhancing the spatial and temporal distributions of low-level atmospheric moisture. Determining the spatial distribution of low-level atmospheric moisture and its source regions during the warm season will forward our understanding of patterns conducive to the development of thunderstorms and dangerous heat waves in the Upper Midwest. By detailing and mapping the evolution of warm season extreme dew point events, we will provide tools to forecasters and other researchers in mitigating the hazards associated with heat waves/heat stress conditions, derechos, and the combination of urban heat and high humidities. We will also inform emergency service agencies and the public of detailed regional risks associated with extreme dew point events.